1. Field of the Invention
The present general inventive concept relates to an image forming apparatus. More particularly, the present general inventive concept relates to a printing head cleaning apparatus usable with an image forming apparatus having a plurality of printing heads that are disposed in a direction transverse to a travel direction of a printing medium, the image forming apparatus having the same, and a method to clean the printing heads.
2. Description of the Related Art
Image forming apparatuses, especially inkjet image forming apparatuses, using ink to form images, may include a shuttle head type, having a carrier formed to reciprocate a printing head to fire ink, and an array head type, having a plurality of printing heads arranged to correspond to a size of a printing medium in a direction transverse to a transferring direction of the printing medium. A printing head usable with the array head type inkjet image forming apparatus may be formed in approximately half or more of the size of the printing medium in a direction transverse to a transferring direction of the printing medium. Two or more printing heads may be arranged in one row or in two rows. The array head type inkjet image forming apparatus may be configured so that the printing heads are stationary and the printing media are moved.
The shuttle head type inkjet image forming apparatus is cheap, has a simple structure but is slow to print. The array head type inkjet image forming apparatus is expensive and has a complex structure compared with the shuttle head type inkjet image forming apparatus, but can print at high speed and/or in high resolution.
However, in inkjet image forming apparatuses having nozzles to fire ink regardless of the shuttle head type and the array head type, ink that has not been moved to the printing medium during a printing operation may remain on the nozzle of the inkjet head after the printing operation. Therefore, if the inkjet image forming apparatus has not been used for a long time, the remaining ink may be solidified and clog the nozzle so that the printing operation cannot be performed normally. In other words, when the inkjet image forming apparatus has not been used for a period of time, the remaining ink may react with outside air so as to be solidified on the nozzle of the printing head. Also, the remaining ink may be solidified with contaminants, such as dust entering from the outside, to clog the nozzle. A phenomenon in that the nozzle is clogged with the solidified ink and/or contaminants is referred to as ‘nozzle clog’. The nozzle clog deteriorates printing quality.
When the nozzle clog occurs, ink is solidified on a nozzle surface of the printing head. Therefore, even when the nozzle surface is cleaned using a dry wiping apparatus, such as a cleaning wiper unit formed to contact and clean the nozzle surface of the printing head before or after the printing operation, it is difficult to remove the solidified ink from the nozzle surface.
To solve this problem, it has been required to develop a printing head cleaning apparatus that can dissolve and remove the solidified ink from the nozzle surface of the printing head.